Renewed interest in wood, coal, peat and other carbonaceous fuels for heating requirements in homes and commercial buildings has been accompanied by a revival of the traditional wood stove and the production and marketing of new varieties of stoves and furnaces for combusting wood and similar fuels. A disadvantage of such currently available stoves is that at best they are inefficient with as much as 70% of the recoverable thermal energy from such fuels lost up the flue or chimney in the form of direct heat and smoke containing constituents of fuel and flue gas volatiles that have been only partially combusted. Thus, as a result of incomplete burning of fuel and failure to efficiently extract and exchange heat generated by portion of the fuel actually combusted, such stoves unlock and make available for heating as little as 30% of the potentially available energy of the carbonaceous fuels. Furthermore, so called "creosote" deposits in flues and chimneys from unburned fuel fractions present health and safety problems and must be removed regularly.